A company recently constructed a financial planning model to predict monthly cash inflows and outflows.

The model is based on various financial relationships including collection patterns of receivables, inventory outflows, expense payments, and so forth, all obtained by analyzing monthly data of the past three years. Before the spreadsheet model is put into use, management insists that 4 employees perform some validity testing to ensure that the model is working properly. Suggest how the model might be tested to ensure that it is, in fact, valid.